<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd">
<html xmlns="http://www.w3.org/1999/xhtml" xml:lang="en" lang="en">
<head>
<title>Ruby Summary: Ruby Study Notes - Best Ruby Guide, Ruby Tutorial</title>
<meta http-equiv="content-type" content="text/html; charset=utf-8" />
<meta name="description" content="Ruby Study Notes - Best Ruby Guide, Ruby Tutorial" />
<meta name="keywords" content="free ruby programming guide,ruby guide,free ruby programming course,best ruby guide,ruby tutorials,ruby tutorial,learn ruby,ruby,ruby on rails,ruby rails,ruby learning,ruby tutoring,learning ruby,ruby programming,ruby on rails development,ruby training" />
<meta name="Distribution" content="Global" />
<meta name="author" content="Satish Talim / Original design: Erwin Aligam - ealigam@gmail.com" />
<meta name="copyright" content="Satish Talim 2007 and beyond..." />
<meta name="verify-v1" content="rFu86se+IkbtF+bH8mgJBKwU5HnKaSd8Ghw9umXQOkM=" />
<meta name="robots" content="index,follow" />
<meta http-equiv="Expires" content="0" />
<meta name="revisit-after" content="1 days" />
<link rel="stylesheet" href="/images/NewOrange.css" type="text/css" />
<link rel="icon" type="image/ico" href="/images/favicon.ico" />
<!-- Google +1 button code -->
<link rel="canonical" href="/satishtalim/ruby_summary9.html" />
<script type="text/javascript" src="https://apis.google.com/js/plusone.js"></script>

<!-- Google Analytics code -->
<script type="text/javascript">

  var _gaq = _gaq || [];
  _gaq.push(['_setAccount', 'UA-59044-10']);
  _gaq.push(['_trackPageview']);

  (function() {
    var ga = document.createElement('script'); ga.type = 'text/javascript'; ga.async = true;
    ga.src = ('https:' == document.location.protocol ? 'https://ssl' : 'http://www') + '.google-analytics.com/ga.js';
    var s = document.getElementsByTagName('script')[0]; s.parentNode.insertBefore(ga, s);
  })();

</script>
<!-- Google Analytics code ends -->
</head>

<body>
<!-- wrap starts here -->
<div id="wrap">

    <div id="header">

        <h1 id="logo">Ruby<span class="orange">Learning.github.io</span></h1>
        <h2 id="slogan">Helping Ruby Programmers become Awesome!</h2>

    </div>

    <div id="menu">
        <ul>
            <li><a href="/" title="Home page for rubylearning.github.io">Home</a></li>
            <li><a href="/satishtalim/tutorial.html" title="Get started Learning Ruby here...">Tutorial</a></li>
            <li><a href="/download/downloads.html" title="Download this tutorial as an eBook">Downloads</a></li>
            <li><a href="/other/testimonials.html" title="People around the world who benefited from this site">Testimonials</a></li>
            <li><a href="/other/certification.html" title="Get certified in Ruby">Certification</a></li>
            <li><a href="/satishtalim/ruby_guide.html" title="Ruby Guide, Mentor">Mentor</a></li>
            <li><a href="https://blog.rubylearning.github.io/" title="Ruby blog of Learning Ruby site">Blog</a></li>
            <li><a href="/satishtalim/tutorial.html" title="Online Ruby Course">Online Course</a></li>
            <li><a href="http://ruby-challenge.rubylearning.github.io/" title="Ruby Programming Challenge for Newbies">Challenge</a></li>
            <li><a href="/satishtalim/about.html" title="Information about Satish Talim">About</a></li>
        </ul>
    </div>

    <!-- content-wrap starts here -->
    <div id="content-wrap">

            <div id="main">
                <!-- google_ad_section_start -->
                <div id="main-inner"><a name="TemplateInfo"></a>
                <h1>Ruby Summary</h1>

                <p class="post-footer align-right">
                  <strong>
                    <a href="/satishtalim/ruby_constants.html">&lt;Constants | </a>
                    <a href="/satishtalim/tutorial.html">TOC | </a>
                    <a href="/satishtalim/ruby_socket_programming.html">Socket Programming&gt;</a>
                  </strong>
                </p>

                <ol>
                  <li>Ruby Modules are similar to classes in that they hold a collection of methods, constants, and other module and class definitions. Unlike classes, you cannot create objects based on modules; instead, you specify that you want the functionality of a particular module to be added to the functionality of a class, or of a specific object.</li>
                  <li>Modules serve two purposes: First they act as namespace, letting you define methods whose names will not clash with those defined elsewhere. Second, they allow you to share functionality between classes - if a class mixes in a module, that module's instance methods become available as if they had been defined in the class. They get mixed in.</li>
                  <li>Observe how we use <b>require</b> or <b>load</b>. <b>require</b> and <b>load</b> take strings as their arguments.<br /><br /><b>require 'motorcycle'</b> or <b>load 'motorcycle.rb'</b><br /><br /><b>include</b> takes the name of a module, in the form of a constant, as in <b>include 'Stuff'</b>.<br /><br />The <b>include</b> method accepts any number of Module objects to mix in:<br /><b>include Enumerable, Comparable</b><br /><br />Although every class is a module, the <b>include</b> method does not allow a class to be included within another class.</li>
                  <li>Remember that you can mix in more than one module in a class. However, a class cannot inherit from more than one class.</li>
                  <li>Class names tend to be nouns, while module names are often adjectives.</li>
                  <li>At every point when your program is running, there is one and only one <strong>self</strong> - the current or default object accessible to you in your program.</li>
                  <li>Please note the rules given for <strong>self</strong> in the <a href="/satishtalim/ruby_self.html">Self</a> related page.</li>
                  <li>Java features the ability to serialize objects, letting you store them somewhere and reconstitute them when needed. Ruby calls this kind of serialization <em>marshaling</em>.</li>
                  <li><strong>Marshal.dump</strong> is used to save a serialized version of an object.</li>
                  <li><strong>Marshal.load</strong> is used to read in from a serialized object.</li>
                  <li>A Ruby constant is a reference to an object.</li>
                  <li>Although constants should not be changed, you can <em>modify</em> the internal states of the objects they reference.</li>
                  <li>Remember the rules for constants.</li>
                </ol>
                <p style="background-color: #FAFAFA; padding: 5px; margin-top: 20px; font-size: 65%;"><strong>Note</strong>: The Ruby Logo is Copyright (c) 2006, Yukihiro Matsumoto. I have made extensive references to information, related to Ruby, available in the public domain (wikis and the blogs, articles of various <span style="font-weight: bold;" title="Click Gurus on the menu above">Ruby Gurus</span>), my acknowledgment and thanks to all of them. Much of the material on <a href="/">rubylearning.github.io</a> and in the course at <a href="http://rubylearning.org/">rubylearning.org</a> is drawn <strong>primarily</strong> from the <strong>Programming Ruby book</strong>, available from <a href="http://pragprog.com/titles/ruby3/programming-ruby-3">The Pragmatic Bookshelf</a>.</p>

                <!-- google_ad_section_end -->
                <p class="post-footer align-right">
                  <strong>
                    <a href="/satishtalim/ruby_constants.html">&lt;Constants | </a>
                    <a href="/satishtalim/tutorial.html">TOC | </a>
                    <a href="/satishtalim/ruby_socket_programming.html">Socket Programming&gt;</a>
                  </strong>
                </p>

            </div>
            <!-- main inner ends here -->
        </div>

            <div id="rightbar">

            </div>

    <!-- content-wrap ends here -->
    </div>

<!-- wrap ends here -->
</div>

<!-- footer starts here -->
<div id="footer">
    <!-- CHANGE THE FOOTER -->
    <p>&copy; 2006-2021 <strong>rubylearning.github.io - A Ruby Tutorial</strong>&nbsp;&nbsp;Page Updated: 5th Jan. 2021 | Design: <a href="mailto:ealigam@gmail.com">Erwin Aligam</a> | Valid: <a href="http://validator.w3.org/check/referer">XHTML</a> | <a href="http://jigsaw.w3.org/css-validator/check/referer">CSS</a>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;<a href="/">Home</a> | <a href="/privacy.html">Privacy</a> | <a href="/sitemap.html">Sitemap</a></p>

</div>
<!-- footer ends here -->
</body>
</html>
